Can nano PZT-OPC composites be used as a smart γ-ray attenuator?

Abstract Nano PbZr0.52Ti0.48O3-ordinary Portland cement (PZT-OPC) composites were fabricated by a ball milling technique with different PZT content (30, 50, 70, and 90% by weight). The prepared samples were annealed at 600 °C. The structure, morphology, thermal and electrical properties of these annealed samples were investigated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA). The effects of PZT on dielectric and piezoelectric properties of the composites were investigated. γ-ray spectroscopy was used to measure the γ-ray attenuation coefficients of the annealed nanocomposite samples using the 661.7 keV γ-ray of 137Cs source. The microstructure changes of the prepared composite samples were investigated using the positron annihilation lifetime (PAL) and Doppler broadening (DB) techniques. The XRD patterns show both PZT and cement peaks. Also, these patterns indicate the presence of PZT retards the hydration process of the Portland cement. The FTIR spectra show the major absorption bands for both PZT and cement. SEM images show the binding between calcium silicate hydrate and PZT which may be a better factor for improving the mechanical properties of the cement. TGA curves show a higher thermal weight loss for 50% PZT-OPC composite sample. The PZT-OPC composite sample with 50% PZT content shows the highest γ-ray mass attenuation coefficient compared with the other composite samples. The positron annihilation spectroscopy (PAS) results show that the size of large voids and the concentration of small defects increase by increasing PZT content. Also, these results reveal that the core electrons slightly reduced by increasing PZT content. The results indicate that the dielectric constant and piezoelectric coefficient values slightly and rapidly increase for composite samples with PZT content 50%, respectively. Finally, the 50% PZT-OPC composite sample showed novel shielding and acceptable piezoelectric properties to be used as a smart shield.